Ionic complexes

ABSTRACT

The present invention provides a phosphopeptide or phosphoprotein (PP) stabilised amorphous calcium phosphate or amorphous calcium fluoride phosphate complex having a calcium ion greater than about 30 moles of calcium per mole of PP

The present invention relates to superloaded complexes of amorphouscalcium phosphate and/or amorphous calcium fluoride phosphate stabilisedby phosphopeptides/phosphoproteins. These superloaded complexes haveanticariogenic properties useful to protect tooth and bone structures asthey remineralize (repair) early stages of dental caries as well asother dental/medical applications (including anti-calculus,anti-erosion/corrosion and anti-dentinal hypersensitivity). Methods ofmaking the superloaded complexes of the invention and of treatment orprevention of dental caries, dental calculus, dental erosion/corrosionand dental hypersensitivity are also provided.

BACKGROUND

Dental caries is initiated by the demineralization of hard tissue of theteeth usually by organic acids produced from fermentation of dietarysugar by dental plaque odontopathogenic bacteria. Dental caries is stilla major public health problem. Further, restored tooth surfaces can besusceptible to further dental caries around the margins of therestoration. Even though the prevalence of dental caries has decreasedthrough the use of fluoride in most developed countries, the diseaseremains a major public health problem. Dental erosion/corrosion is theloss of tooth mineral by dietary or regurgitated acids. Dentalhypersensitivity is due to exposed dentinal tubules through loss of theprotective mineralized layer, cementum and dental calculus is theunwanted accretion of calcium phosphate minerals on the tooth surface.All these conditions, dental caries, dental erosion/corrosion, dentalhypersensitivity and dental calculus are therefore imbalances in thelevel of calcium phosphates. Dental caries, dental erosion/corrosion anddental hypersensitivity can be treated with stabilized amorphous calciumphosphate (ACP) by providing bioavailable calcium and phosphate ions toreplace the lost calcium phosphate mineral. Stabilized ACP can also bindto the surface of dental calculus and prevent further accretion.Stabilized ACP and stabilized amorphous calcium fluoride phosphate(ACFP) therefore can play a major role in preventing and treating oraldiseases and other medical conditions.

Casein is present in milk in the form of micelles, which are believed tobe roughly spherical particles with a radius of about 100 nm, dispersedin a continuous phase of water, salt, lactose and whey proteins. Thecasein micelles serve as a carrier of calcium phosphate providing abioavailable source of calcium and phosphate ions for bone and teethformation. The ability of casein micelles to maintain calcium andphosphate ions in a soluble and bioavailable state is retained by thetryptic multiphosphorylated peptides of the caseins known as the caseinphosphopeptides (CPP). WO 98/40406 describes caseinphosphopeptide-amorphous calcium phosphate complexes (CPP-ACP) andCPP-stabilised amorphous calcium fluoride phosphate complexes (CPP-ACFP)which have been produced at alkaline pH. Such complexes have been shownto prevent enamel demineralization and promote remineralization ofenamel subsurface lesions in animal and human in situ caries models.

The phosphopeptides which are active in forming the complexes do sowhether or not they are part of a full-length casein protein. The activecasein phosphopeptides (CPP) formed by tryptic digestion have beenspecified in U.S. Pat. No. 5,015,628 and include peptides Bosα_(s1)-casein X-5P (f59-79) [1], Bos β-casein X-4P (f1-25) [2], Bosα_(s2)-casein X-4P (f46-70) [3] and Bos α_(s2)-casein X-4P (f1-21) [4]as follows:

[1] Gln⁵⁹-Met-Glu-Ala-Glu-Ser(P)-Ile-Ser(P)-Ser(P)-Ser(P)-Glu-Glu-Ile-Val-Pro-Asn- Ser(P)-Val-Glu-Gln-Lys⁷⁹α_(s1)(59-79) [2] Arg¹-Glu-Leu-Glu-Glu-Leu-Asn-Val-Pro-Gly-Glu-Ile-Val-Glu-Ser(P)-Leu-Ser(P)-Ser(P)-Ser(P)-Glu-Glu-Ser-Ile-Thr-Arg²⁵ β(1-25) [3]Asn⁴⁶-Ala-Asn-Glu-Glu-Glu-Tyr-Ser-Ile-Gly-Ser(P)-Ser(P)-Ser(P)-Glu-Glu-Ser(P)-Ala-Glu-Val-Ala-Thr-Glu-Glu-Val-Lys⁷⁰ αs2(46-70) [4]Lys¹-Asn-Thr-Met-Glu-His-Val-Ser(P)-Ser(P)-Ser(P)-Glu-Glu-Ser-Ile-Ile-Ser(P)- Gln-Glu-Thr-Tyr-Lys²¹αs2(1-21)

Other casein phosphopeptides that have activity in assisting in thestabilization of superloaded amorphous calcium phosphate complexes arethose peptides containing the sequences Ser(P)-Xaa-Glu/Ser(P) whereSer(P) represents a phosphoseryl residue. Therefore thephosphopeptides/phosphoproteins active in stabilizing superloadedamorphous calcium phosphate and amorphous calcium fluoride phosphatecomplexes are those containing the sequence -A-B-C-, where A is aphosphamino acid, preferably phosphoserine; B is any amino acidincluding a phosphoamino acid and C is one of the glutamate, aspartateor a phosphoamino acid.

Amorphous calcium phosphate stabilized by casein phosphopeptides asdescribed in WO 98/40406 is available commercially in a product sold asRecaldent™ as provided by Recaldent Pty Ltd, Victoria, Australia.However, it would be desirable for an even more effective form ofamorphous calcium phosphate stabilized by casein phosphopeptides to beavailable for treatments. Further, when Recaldent™ is dissolved in acarrier such as distilled water, there is inevitable leakage of ionsinto the surrounding water to form an equilibrium. This will, in someuses, reduce the calcium phosphate deliverable by the composition, suchas for a treatment.

SUMMARY OF THE INVENTION

In one aspect, the present invention provides a “superloaded”phosphopeptide or phosphoprotein (PP) stabilized-amorphous calciumphosphate (ACP) or amorphous calcium fluoride phosphate (ACFP) complex.The complex may be formed at any pH (eg 3-10). Preferably thephosphopeptide includes the sequence -A-B-C-, where A is a phosphoaminoacid, preferably phosphoserine, B is any amino acid including aphosphoamino acid and C is glutamic acid, aspartic acid or aphosphoamino acid. The phosphoamino acid may be phosphoserine. The PP issuperloaded with calcium and phosphate ions. The calcium ions may be inthe range 30-1000 mol Ca per mole of PP, or in the range of 30-100 or30-50 mole Ca per mole of PP. In another embodiment, the mol Ca per molof PP is at least 25, 30, 35, 40, 45 or 50. The phosphate ions willtypically be present in a ratio to the calcium ions (Ca:P) of 1.5-1.8:1.In one embodiment, the ratio is about 1.58:1.

In a further aspect the present invention provides a phosphopeptide orphosphoprotein (PP) stabilized amorphous calcium phosphate or amorphouscalcium fluoride phosphate complex having a calcium ion content greaterthan about 30 moles of calcium per mole of PP.

In a preferred embodiment, the calcium ion content is in the range ofabout 30 to 100 moles of calcium per mole of PP. More preferably, thecalcium ion content is in the range of about 30 to about 50 moles ofcalcium per mole of PP.

The present invention further relates to an aqueous formulation of thePP stabilized ACP or ACFP complex described above.

It will also be understood that the term “comprises” (or its grammaticalvariants) as used in this specification is equivalent to the term“includes” and may be used interchangeably and should not be taken asexcluding the presence of other elements or features.

Surprisingly, the activity of casein phosphopeptide-amophous calciumphosphate (CPP-ACP) as produced using the method described in WO98/40406, in remineralizing (repairing) enamel subsurface lesions (earlystages of tooth decay) can be substantially increased by superloadingthe casein phosphopeptides with calcium and phosphate ions beyond theamount expected to be possible. The calcium can be in the form of CaHPO₄or calcium lactate and sodium hydrogen phosphate or any other suitableform of calcium salt or phosphate salt.

The PP of the complexes of the present invention may be a caseinphosphopeptide (CPP) which may be intact casein or a fragment of casein.The CPP-amorphous calcium phosphate complex formed may be a colloidalcomplex, where the core particles aggregate to form large (eg 100 nm)colloidal particles suspended in water.

The PP may be from any source; it may be present in the context of alarger polypeptide, including a full length casein polypeptide, or itmay be isolated by tryptic or chemical (eg alkaline hydrolysis)digestion of casein or other phosphoamino acid rich proteins such asphosvitin, or by chemical or recombinant synthesis, provided that itcomprises the sequence -A-B-C-. The sequence flanking this core sequencemay be any sequence. However, those flanking sequences in α_(s1)(59-79)[1], β(1-25) [2], α_(s2)(46-70) [3] and α_(s2)(1-21) [4] are preferred.The flanking sequences may optionally be modified by deletion, additionor conservative substitution of one or more residues. The amino acidcomposition and sequence of the flanking region are not criticalalthough the preferred flanking regions appear to contribute to thestructural action of the motif to maintain the conformation of thepeptide so that all phosphoryl and carboxyl groups may interact withcalcium ions.

In a preferred embodiment, the PP is selected from the group consistingof α_(s1)(59-79) [1], P(1-25) [2], α_(s2)(46-70) [3] and α_(s2)(1-21)[4].

In a preferred embodiment, at least 40% by weight of the PP in thePP-stabilised ACP or ACFP is a mixture of proteins or protein fragmentswhich are or contain one or more of the peptides [1] to [4] above.Preferably, at least 60%, more preferably at least 70%, by weight of thePP in the PP-stabilised ACP or ACFP is a mixture of proteins or proteinfragments which are or contain the peptides [1] to [4].

The phosphopeptide is believed to stabilize the superloaded calcium,phosphate (and fluoride) to produce a metastable solution. This bindingis believed to inhibit the growth of ACP or ACFP to a size thatinitiates nucleation and precipitation of calcium phosphate. In thisway, calcium and other ions such as fluoride ions can be localised, forinstance at a surface on a tooth to prevent demineralization and preventor reduce formation of dental caries.

Thus, in a further aspect, the invention provides a stable, superloadedACFP complex or a stable, superloaded ACP complex as described above,which complex acts as a delivery vehicle that co-localises ionsincluding, but not limited to calcium, fluoride and phosphate ions at atarget site. In a preferred embodiment, the complex is in a slow-releaseamorphous form that produces superior anti-caries efficacy. The targetsite is preferably teeth or bone.

In a further aspect, the invention also provides a method of producing astable, superloaded complex of ACP or ACFP as described above,comprising the steps of:

-   (i) obtaining solutions comprising calcium, inorganic phosphate and    fluoride (optional); and-   (ii) admixing (i) with a solution comprising PP-ACP.

In a preferred embodiment, the PP is casein phosphopeptide (CPP).

In a further aspect of the present invention there is provided a methodfor increasing the calcium (and phosphate) ion content as ACP/ACFP of aPP stabilized-ACP and/or ACFP including the steps of

-   (i) obtaining solutions comprising calcium, inorganic phosphate and    fluoride (optional); and-   (ii) admixing (i) with a solution comprising PP-ACP and/or PP-ACFP.    or-   (i) obtaining powders containing calcium eg CaHPO₄, calcium lactate,    etc. and-   (ii) admixing (i) with a PP-ACP and/or PP-ACFP powder.

It has been found that increasing the calcium phosphate loading ofPP-ACP complexes in the commercial product known as Recaldent™ mayresult in a higher viscosity preparation than is suitable for aparticular application. Accordingly, it is useful for some applicationsto prepare the superloaded complexes by dry blending the PP-ACP withcalcium phosphate (particularly CaHPO₄) for subsequent incorporationinto a formulation, for example an oral care formulation such as atoothpaste or chewing gum.

In a further aspect of the present invention there is provided a methodfor producing a phosphopeptide or phosphoprotein (PP) stabilizedamorphous calcium phosphate (ACP) and/or amorphous calcium fluoridephosphate (ACFP) complex having a calcium ion content above about 30moles of calcium per mole of PP including the steps of:

-   (i) obtaining a solution including a PP-ACP and/or PP-ACFP complex;    and-   (ii) mixing with calcium and phosphate ions, while maintaining the    solution at a pH of less than 7.

In a further aspect of the present invention there is provided aformulation of a PP stabilized ACP and/or ACFP complex together with atleast an equal amount by weight of calcium phosphate. Preferably thecalcium phosphate is CaHPO₄. Preferably, the calcium phosphate (e.g.CaHPO₄) is dry blended with the PP stabilized ACP and/or ACFP complex.In a preferred embodiment, the PP-ACP and/or PP-ACFP complex:calciumphosphate ratio is about 1:1-50. more preferably about 1:1-25, morepreferably about 1:5-15. In one embodiment, the PP-ACP and/or PP-ACFPcomplex:calcium phosphate ratio is about 1:10.

In a further aspect of the present invention there is provided an oralcare composition including a formulation of a PP stabilized ACP and/orACFP complex together with at least an equal amount by weight of calciumphosphate as described above.

In a further aspect of the present invention there is provided a methodfor producing an oral care formulation that includes a phosphopeptide orphosphoprotein (PP) stabilized amorphous calcium phosphate (ACP) and/oramorphous calcium fluoride phosphate (ACFP) complex having a calcium ioncontent greater than about 30 moles of calcium per mole of PP when usedin the oral cavity including the steps of:

-   (i) obtaining a powder including a PP-ACP and/or PP-ACFP complex;-   (ii) dry blending with an effective amount of calcium phosphate; and-   (iii) formulating the dry blended PP-ACP and/or PP-ACFP and calcium    phosphate mixture into an oral care formulation.

Preferably, the form of calcium phosphate for dry blending is CaHPO₄.

Preferably the oral care formulation is selected from the groupconsisting of a toothpaste, a tooth crème; a chewing gum; lozenge; amouthwash and a tooth powder. Without being bound by any theory or modeof action, it is believed that the “superloaded” phosphopeptide is ableto deliver a sufficiently high concentration of calcium and phosphateions, especially ACP and ACFP as the case may be, despite the inherentdilution resulting from the incorporation of the complexes into aphysiologically acceptable carrier, and further dilution in, forexample, saliva in dental applications. It thus maintains the ionicspeciation of the calcium and phosphate ions. The invention is directedto greater amounts of ACP-ACFP at the site of delivery. This can beachieved by a starting material of higher ACP/ACFP content and/orreduced loss or leakage of ACP/ACFP between manufacture and use.

These superloaded complexes are also useful as dietary supplements insubjects who for any reason, such as dietary intolerance, allergy, orreligious or cultural factors, are unable or unwilling to consume dairyproducts in an amount sufficient to supply their dietary calciumrequirements. The superloaded complexes of the invention are useful ascalcium supplements in subjects in need of stimulation of bone growth,for example subjects undergoing fracture repair, joint replacement, bonegrafts, or craniofacial surgery.

In a further aspect of the present invention there is provided a methodfor remineralizing teeth comprising applying to the teeth a superloadedcomplex as described above, desirably in a pharmaceutically acceptablecarrier. The complex may contain calcium phosphate, calcium fluoride orboth. The method is preferably applied to a subject in need oftreatment.

In a further aspect, the present invention provides a method forremineralizing a dental surface or subsurface including applying to thedental surface or subsurface a phosphopeptide or phosphoprotein (PP)stabilized amorphous calcium phosphate and/or amorphous calcium fluoridephosphate complex having a calcium ion content greater than about 30moles of calcium per mole of PP.

In a further aspect of the present invention there is provided the useof a phosphopeptide or phosphoprotein (PP) stabilized amorphous calciumphosphate and/or amorphous calcium fluoride phosphate complex having acalcium ion content greater than about 30 moles of calcium per mole ofPP in the manufacture of a medicament for remineralizing a dentalsurface or subsurface.

In a further aspect of the present invention there is provided the useof a phosphopeptide or phosphoprotein (PP) stabilized amorphous calciumphosphate and/or amorphous calcium fluoride phosphate complex having acalcium ion content greater than about 30 moles of calcium per mole ofPP for remineralizing a dental surface or subsurface.

Preferably the dental surface or subsurface is dental enamel, morepreferably a surface or subsurface lesion in the dental enamel.

The stable ACFP or ACP superloaded complex may be incorporated into orform in oral care compositions such as toothpaste, mouth washes orformulations for the mouth. This may, for example, aid in the preventionand/or treatment of dental caries or tooth decay. The ACFP or ACPsuperloaded complex (which may comprise solely CPP-ACP and/or -ACFPcomplexes, or CPP-ACP and/or -ACFP complexes with calcium phosphate,e.g. CaHPO₄) may comprise 0.01-50% by weight of the composition,preferably 0.1%-25%, more preferably 0.5%-20% and optionally 0.5%-10%.For oral compositions, it is preferred that the amount of the CPP-ACPand/or CPP-ACFP administered is 0.01-50% by weight, preferably 0.5%-20%or 0.5%-10% by weight of the composition. In a particularly preferredembodiment, the oral composition of the present invention contains about1-5% superloaded CPP-ACP (sCPP-ACP). The oral composition of thisinvention which contains the above-mentioned agents may be prepared andused in various forms applicable to the mouth such as dentifriceincluding toothpastes, toothpowders and liquid dentifrices, mouthwashes,troches, chewing gums, dental pastes, gingival massage creams, gargletablets, dairy products and other foodstuffs. The oral compositionaccording to this invention may further include additional well knowningredients depending on the type and form of a particular oralcomposition.

In certain preferred forms of the invention the oral composition may besubstantially liquid in character, such as a mouthwash or rinse. In sucha preparation the vehicle is typically a water-alcohol mixture desirablyincluding a humectant as described below. Generally, the weight ratio ofwater to alcohol is in the range of from about 1:1 to about 20:1. Thetotal amount of water-alcohol mixture in this type of preparation istypically in the range of from about 70 to about 99.9% by weight of thepreparation. The alcohol is typically ethanol or isopropanol. Ethanol ispreferred.

The pH of such liquid and other preparations of the invention isgenerally in the range of from about 3 to about 10 and typically fromabout 5.0 to 7.0. The pH can be controlled with acid (e.g. citric acidor benzoic acid) or base (e.g. sodium hydroxide) or buffered (as withsodium citrate, benzoate, carbonate, or bicarbonate, disodium hydrogenphosphate, sodium dihydrogen phosphate, etc).

In one embodiment, the oral composition according to the presentinvention has a pH of about 5.5.

Accordingly, in a further aspect of the present invention there isprovided a composition for remineralizing a dental surface or subsurfaceincluding a phosphopeptide or phosphoprotein (PP) stabilized amorphouscalcium phosphate and/or amorphous calcium fluoride phosphate complexhaving a calcium ion content greater than about 30 moles of calcium permole of PP together with a pharmaceutically acceptable carrier and/orexcipient.

In a further aspect of the present invention there is provided acomposition for remineralizing a dental surface or subsurface consistingessentially of a phosphopeptide or phosphoprotein (PP) stabilizedamorphous calcium phosphate and/or amorphous calcium fluoride phosphatecomplex having a calcium ion content greater than about 30 moles ofcalcium per mole of PP together with a pharmaceutically acceptablecarrier and/or excipient.

In another embodiment, the oral composition according to the presentinvention contains a calcium chelator, eg. pyrophosphate, polyphosphate,citrate, EDTA, etc.

In other desirable forms of this invention, the oral composition may besubstantially solid or pasty in character, such as toothpowder, a dentaltablet or a toothpaste (dental cream) or gel dentifrice. The vehicle ofsuch solid or pasty oral preparations generally contains dentallyacceptable polishing material. Examples of polishing materials arewater-insoluble sodium metaphosphate, potassium metaphosphate,tricalcium phosphate, dihydrated calcium phosphate, anhydrous dicalciumphosphate, calcium pyrophosphate, magnesium orthophosphate, trimagnesiumphosphate, calcium carbonate, hydrated alumina, calcined alumina,aluminum silicate, zirconium silicate, silica, bentonite, and mixturesthereof. Other suitable polishing material include the particulatethermosetting resins such as melamine-, phenolic, andurea-formaldehydes, and cross-linked polyepoxides and polyesters.Preferred polishing materials include crystalline silica having particlesizes of up to about 5 microns, a mean particle size of up to about 1.1microns, and a surface area of up to about 50,000 cm²/g., silica gel orcolloidal silica, and complex amorphous alkali metal aluminosilicate.

When visually clear gels are employed, a polishing agent of colloidalsilica, such as those sold under the trademark SYLOID as Syloid 72 andSyloid 74 or under the trademark SANTOCEL as Santocel 100, alkali metalaluminosilicate complexes are particularly useful since they haverefractive indices close to the refractive indices of gellingagent-liquid (including water and/or humectant) systems commonly used indentifrices.

Many of the so-called “water insoluble” polishing materials are anionicin character and also include small amounts of soluble material. Thus,insoluble sodium metaphosphate may be formed in any suitable manner, forexample as illustrated by Thorpe's Dictionary of Applied Chemistry,Volume 9, 4th Edition, pp. 510-511. The forms of insoluble sodiummetaphosphate known as Madrell's salt and Kurrol's salt are furtherexamples of suitable materials. These metaphosphate salts exhibit only aminute solubility in water, and therefore are commonly referred to asinsoluble metaphosphates (IMP). There is present therein a minor amountof soluble phosphate material as impurities, usually a few percent suchas up to 4% by weight. The amount of soluble phosphate material, whichis believed to include a soluble sodium trimetaphosphate in the case ofinsoluble metaphosphate, may be reduced or eliminated by washing withwater if desired. The insoluble alkali metal metaphosphate is typicallyemployed in powder form of a particle size such that no more than 1% ofthe material is larger than 37 microns.

The polishing material is generally present in the solid or pastycompositions in weight concentrations of about 10% to about 99%.Preferably, it is present in amounts from about 10% to about 75% intoothpaste, and from about 70% to about 99% in toothpowder. Intoothpastes, when the polishing material is silicious in nature, it isgenerally present in an amount of about 10-30% by weight. Otherpolishing materials are typically present in amount of about 30-75% byweight.

In a toothpaste, the liquid vehicle may comprise water and humectanttypically in an amount ranging from about 10% to about 80% by weight ofthe preparation. Glycerine, propylene glycol, sorbitol and polypropyleneglycol exemplify suitable humectants/carriers. Also advantageous areliquid mixtures of water, glycerine and sorbitol. In clear gels wherethe refractive index is an important consideration, about 2.5-30% w/w ofwater, 0 to about 70% w/w of glycerine and about 20-80% w/w of sorbitolare preferably employed.

Toothpaste, creams and gels typically contain a natural or syntheticthickener or gelling agent in proportions of about 0.1 to about 10,preferably about 0.5 to about 5% w/w. A suitable thickener is synthetichectorite, a synthetic colloidal magnesium alkali metal silicate complexclay available for example as Laponite (e.g. CP, SP 2002, ID) marketedby Laporte Industries Limited. Laponite D is, approximately by weight58.00% SiO₂, 25.40% MgO, 3.05% Na₂O, 0.98% Li₂O, and some water andtrace metals. Its true specific gravity is 2.53 and it has an apparentbulk density of 1.0 g/ml at 8% moisture.

Other suitable thickeners include Irish moss, iota carrageenan, gumtragacanth, starch, polyvinylpyrrolidone, hydroxyethylpropylcellulose,hydroxybutyl methyl cellulose, hydroxypropyl methyl cellulose,hydroxyethyl cellulose (e.g. available as Natrosol), sodiumcarboxymethyl cellulose, and colloidal silica such as finely groundSyloid (e.g. 244). Solubilizing agents may also be included such ashumectant polyols such propylene glycol, dipropylene glycol and hexyleneglycol, cellosolves such as methyl cellosolve and ethyl cellosolve,vegetable oils and waxes containing at least about 12 carbons in astraight chain such as olive oil, castor oil and petrolatum and esterssuch as amyl acetate, ethyl acetate and benzyl benzoate.

It will be understood that, as is conventional, the oral preparationsare to be sold or otherwise distributed in suitable labelled packages.Thus, a jar of mouthrinse will have a label describing it, in substance,as a mouthrinse or mouthwash and having directions for its use; and atoothpaste, cream or gel will usually be in a collapsible tube,typically aluminium, lined lead or plastic, or other squeeze, pump orpressurized dispenser for metering out the contents, having a labeldescribing it, in substance, as a toothpaste, gel or dental cream.

Organic surface-active agents may be used in the compositions of thepresent invention to achieve increased prophylactic action, assist inachieving thorough and complete dispersion of the active agentthroughout the oral cavity, and render the instant compositions morecosmetically acceptable. The organic surface-active material ispreferably anionic, nonionic or ampholytic in nature and preferably doesnot interact with the active agent. It is preferred to employ as thesurface-active agent a detersive material which imparts to thecomposition detersive and foaming properties. Suitable examples ofanionic surfactants are water-soluble salts of higher fatty acidmonoglyceride monosulfates, such as the sodium salt of the monosulfatedmonoglyceride of hydrogenated coconut oil fatty acids, higher alkylsulfates such as sodium lauryl sulfate, alkyl aryl sulfonates such assodium dodecyl benzene sulfonate, higher alkylsulfo-acetates, higherfatty acid esters of 1,2-dihydroxy propane sulfonate, and thesubstantially saturated higher aliphatic acyl amides of lower aliphaticamino carboxylic acid compounds, such as those having 12 to 16 carbonsin the fatty acid, alkyl or acyl radicals, and the like. Examples of thelast mentioned amides are N-lauroyl sarcosine, and the sodium,potassium, and ethanolamine salts of N-lauroyl, N-myristoyl, orN-palmitoyl sarcosine which should be substantially free from soap orsimilar higher fatty acid material. The use of these sarconite compoundsin the oral compositions of the present invention is particularlyadvantageous since these materials exhibit a prolonged marked effect inthe inhibition of acid formation in the oral cavity due to carbohydratesbreakdown in addition to exerting some reduction in the solubility oftooth enamel in acid solutions. Examples of water-soluble nonionicsurfactants suitable for use are condensation products of ethylene oxidewith various reactive hydrogen-containing compounds reactive therewithhaving long hydrophobic chains (e.g. aliphatic chains of about 12 to 20carbon atoms), which condensation products (“ethoxamers”) containhydrophilic polyoxyethylene moieties, such as condensation products ofpoly (ethylene oxide) with fatty acids, fatty alcohols, fatty amides,polyhydric alcohols (e.g. sorbitan monostearate) and polypropyleneoxide(e.g. Pluronic materials).

The surface active agent is typically present in amount of about 0.1-5%by weight. It is noteworthy, that the surface active agent may assist inthe dissolving of the active agent of the invention and thereby diminishthe amount of solubilizing humectant needed.

Various other materials may be incorporated in the oral preparations ofthis invention such as whitening agents, preservatives, silicones,chlorophyll compounds and/or ammoniated material such as urea,diammonium phosphate, and mixtures thereof. These adjuvants, wherepresent, are incorporated in the preparations in amounts which do notsubstantially adversely affect the properties and characteristicsdesired.

Any suitable flavouring or sweetening material may also be employed.Examples of suitable flavouring constituents are flavouring oils, e.g.oil of spearmint, peppermint, wintergreen, sassafras, clove, sage,eucalyptus, marjoram, cinnamon, lemon, and orange, and methylsalicylate. Suitable sweetening agents include sucrose, lactose,maltose, sorbitol, xylitol, sodium cyclamate, perillartine, AMP(aspartyl phenyl alanine, methyl ester), saccharine, and the like.Suitably, flavour and sweetening agents may each or together comprisefrom about 0.1% to 5% more of the preparation.

The invention also provides use of a composition as described above. Inthe preferred practice of this invention an oral composition accordingto this invention such as mouthwash or dentifrice containing thecomposition of the present invention is preferably applied regularly tothe gums and teeth, such as every day or every second or third day orpreferably from 1 to 3 times daily, at a pH, preferably of about 3.0 toabout 10.0 or more preferably 5.0 to about 9.0, for at least 2 weeks upto 8 weeks or more up to a lifetime. In one embodiment, the pH of theoral composition is about 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0.

The compositions of this invention can also be incorporated in lozenges,or in chewing gum or other products, e.g. by stirring into a warm gumbase or coating the outer surface of a gum base, illustrative of whichare jelutong, rubber latex, vinylite resins, etc., desirably withconventional plasticizers or softeners, sugar or other sweeteners orsuch as glucose, sorbitol and the like.

In another embodiment, the complex of the invention is formulated toform a dietary supplement preferably comprising 0.1-100% w/w, morepreferably 1-50% w/w, most preferably 1-10% and particularly 2% w/w of acomestible. The complex may also be incorporated into food products.

In a further aspect, the invention provides compositions includingpharmaceutical compositions comprising any of the superloaded ACFPand/or ACP complexes as described above together with apharmaceutically-acceptable carrier. Such compositions may be selectedfrom the group consisting of dental, anticariogenic compositions,therapeutic compositions and dietary supplements. Dental compositions ortherapeutic compositions may be in the form of a gel, liquid, solid,powder, cream or lozenge. Therapeutic compositions may also be in theform of tablets or capsules. In one embodiment, the superloaded ACPand/or ACFP complexes are substantially the only remineralizing activecomponents of such a composition. In a further embodiment thesuperloaded ACP and/or ACFP complexes form after the composition, as anoral care composition, is contacted with saliva in the oral cavity.

In a further aspect, there is provided a method of treating orpreventing dental caries or tooth decay, dental erosion/corrosion,dentinal hypersensitivity and dental calculus comprising the step ofadministering a complex or composition of the invention to the teeth orgums of a subject in need of such treatments. Topical administration ofthe complex is preferred.

According to a further aspect of the invention there is provided acomposition for dental restoration, including a dental restorativematerial to which has been added a superloaded ACFP and/or ACP complexaccording to the present invention. The base of the dental restorativematerial can be a glass ionomer cement, a composite material or anyother restorative material which is compatible. It is preferred that theamount of superloaded CPP-ACP complex or superloaded CPP-ACFP complexincluded in the dental restorative material is 0.01-80% by weight,preferably 0.5-10% and more preferably 1-5% by weight. The dentalrestorative material of this invention which contains the abovementioned agents may be prepared and used in various forms applicable todental practice. The dental restorative material according to thisinvention may further include other ions, eg. antibacterial ions Zn²⁺,Ag⁺, etc or other additional ingredients depending on the type and formof a particular dental restorative material. It is preferable that thepH of the superloaded CPP-ACP complex or superloaded CPP-ACFP complex bebetween 2-10, more preferably 5-9 and even more preferably 5-7. It ispreferable that the pH of the dental restorative material containing thesuperloaded CPP-ACP complex or superloaded ACFP complex be between 2-10,more preferably 5-9 and even more preferably 5-7.

The invention is also directed to a method of manufacture of arestorative composition. Preferably, the method includes the addition ofa superloaded ACP and/or ACFP complex as described above, to a basedental restorative material. The invention also relates to use of arestorative composition as stated above for the treatment and/orprevention of dental caries.

In a further aspect of the present invention there is provided a kit foruse in the preparation of a composition for dental restoration including(a) dental restorative material and (b) a phosphopeptide orphosphoprotein (PP) stabilized amorphous calcium phosphate and/oramorphous calcium fluoride phosphate complex having a calcium ioncontent greater than about 30 moles of calcium per mole of PP. The kitmay optionally include instructions for use for the preparation of acomposition for dental restoration.

In a preferred embodiment, the dental restorative material is a porousdental cement. In a further preferred embodiment, the dental restorativematerial is a glass ionomer cement. Without being bound by any theory ormode of action, it is believed that micropores in certain types ofporous dental cement, such as glass ionomer cements, allow the passageof the complexes of the present invention to the dental surface topromote remineralization of the dental material.

The invention also relates to a kit for use in the preparation of acomposition for dental restoration including (a) dental restorativematerial and (b) superloaded CPP-ACP complex and/or superloaded CPP-ACFPcomplex. The kit may optionally include instructions for use for thepreparation of a composition for dental restoration.

The invention also relates to a kit for use in the preparation of acomposition for dental restoration including (a) dental restorativematerial (b) casein phosphopeptide (c) calcium ions and (d) phosphateions, and optionally fluoride ions. The kit may optionally includeinstructions for use for the preparation of a composition for dentalrestoration.

The invention also provides a method of treatment and/or prevention ofdental caries, dental erosion/corrosion, dental hypersensitivity anddental calculus in animals including humans including providing thecomposition according to the invention, or manufactured according to theinvention, and applying to teeth in an animal in need of treatmentand/or prevention.

In a further aspect, the invention relates to methods of treating one ormore conditions related to calcium loss from the body, especially fromthe bones, calcium deficiency, calcium malabsorption, or the like.Examples of such conditions include, but are not limited to,osteoporosis and osteomalacia. In general any condition which can beimproved by increased calcium bioavailability is contemplated.

In a further aspect of the present invention there is provided the useof a phosphopeptide or phosphoprotein (PP) stabilized amorphous calciumphosphate and/or amorphous calcium fluoride phosphate complex having acalcium ion content greater than about 30 moles of calcium per mole ofPP in the manufacture of a composition for the treatment and/orprevention of dental caries, dental erosion/corrosion, dentalhypersensitivity, and/or dental calculus.

In a further aspect of the present invention there is provided the useof a composition including a phosphopeptide or phosphoprotein (PP)stabilized amorphous calcium phosphate and/or amorphous calcium fluoridephosphate complex having a calcium ion content greater than about 30moles of calcium per mole of PP for the treatment and/or prevention ofdental caries, dental erosion/corrosion, dental hypersensitivity, ordental calculus.

It will be clearly understood that, although this specification refersspecifically to applications in humans, the invention is also useful forveterinary purposes. Thus in all aspects the invention is useful fordomestic animals such as cattle, sheep, horses and poultry; forcompanion animals such as cats and dogs; and for zoo animals.

In the figures:

FIG. 1: Enhanced remineralization of enamel subsurface lesions in vitroby CPP superloaded with calcium and phosphate ions.

FIG. 2. Enhanced remineralization of enamel subsurface lesions in situby toothpaste containing CPP superloaded with calcium phosphate.

The invention will now be described with reference to the followingnon-limiting examples.

EXAMPLE 1

Recaldent™ (CPP-ACP) was purchased from Recaldent Pty Ltd, Victoria,Australia. The product (#841117) contained 14.3% calcium, 22.3%phosphate and 47% casein phosphopeptide on a weight basis. The productwas dissolved at 0.5% and adjusted to pH 5.5 by the addition of HCl.Calcium and phosphate ions were then added by titrating 3.25 M CaCl₂ and2M NaH₂PO₄ while keeping the pH at 5.5 with the addition of 2.5 M NaOH.The titration of calcium and phosphate ions was continued until thesolution became translucent. The concentration of calcium and phosphateadded was recorded. The solution may also be formed by titrating calciumand phosphate ions into a 0.5% CPP-ACP solution and letting the pH fallto 5.5 by the addition of further calcium phosphate.

TABLE 1 Calcium and phosphate levels of normal and superloaded CPP-ACPCalcium Phosphate mmol/L mol/mol CPP mmol/L mol/mol CPP Normal 0.5% w/v17.8 22.8 11.6 14.8 CPP-ACP Superloaded 0.5 37.8 48.3 23.6 30.2 w/vCPP-ACP (sCPP-ACP)

These results demonstrate that CPP-ACP can be superloaded with calciumand phosphate ions to produce thermodynamically stable complexes in ametastable solution.

EXAMPLE 2

In another example Recaldent™ (CPP-ACP) powder was dry blended withCaHPO₄ powder in the ratio CPP-ACP:CaHPO₄ equals 1:10 on a weight basis.This powder was then added to sugar-free gum and toothpaste formulationsat 1-5% w/w.

EXAMPLE 3 Comparison of Remineralization of Enamel Subsurface Lesions InVitro by Normal CPP-ACP and Superloaded CPP-ACP (sCPP-ACP)

The polished enamel surface of extracted human third molars were sawn asa slab (8×4 mm²) and covered with acid resistant nail varnish to form anocclusal-half and a gingival-half mesiodistal window (1×7 mm²) separatedby 1 mm [Reynolds E. C. (1997) J. Dent. Res. 76, 1587-1595]. Subsurfaceenamel lesions were created in these windows using the Carbopol methodof White [White D. J. (1987) Caries Res 21, 228-242] as modified byReynolds [Reynolds E. C. (1997) J. Dent. Res. 76, 1587-1595]. The enamelslabs were sawn in half to 4×4 mm² blocks. The gingival-half lesion onone block and the occlusal-half lesion on the other block were sealedwith varnish to create the demineralized controls as described byReynolds [Reynolds E. C. (1997) J. Dent. Res. 76, 1587-1595].

The enamel half-lesions were exposed to the two differentremineralization solutions for 10 days at 37° C. without mixing. Theremineralization solutions were 0.5% w/v CPP-ACP adjusted to pH 5.5 withHCl and superloaded CPP-ACP prepared in Example 1.

After remineralization each pair of blocks was dehydrated in ethanol andembedded in methyl-methacrylate resin (Paladur, Kulzer, Germany). Three200-300 μm sections were cut perpendicular to the lesion surface, lappeddown to 80±5 μm and radiographed beside an aluminium stepwedge of 10×14μm thick increments as described previously.

Radiographic images of the lesions were viewed via transmitted lightthrough a Dilux 22 microscope (Ernst Leitz Wetzlar, Germany). The imageswere acquired by video camera (Sony DXC 930P) and digitized (Scionimaging corporation, colour grabber 7) under the control of imagingsoftware (Optimas 6.2). Images of the lesions, controls and thealuminium stepwedge were scanned as previously described by Shen et al.[Shen P. et al., (2001) J. Dent. Res. 80, 2066-2070]. The enamel sectionthickness was measured and volume percentage mineral data determinedusing the equation of Angmar [Angmar B. et al., (1963) UltrastructuralRes 8, 12-23] as previously described by Shen at al. [Shen P. et al.,(2001) J. Dent. Res. 80, 2066-2070]. The percentage remineralization (%R) was also calculated as previously described by Shen et al. [Shen P.et al., (2001) J. Dent. Res. 80, 2066-2070].

The remineralization of the enamel subsurface lesions is shown in FIG.1.

The results of FIG. 1 demonstrate that a superloaded CPP-ACP (sCPP-ACP)solution is superior to a normal CPP-ACP solution in remineralization ofenamel subsurface lesions in vitro.

EXAMPLE 4

The ability of toothpaste formulations containing superloaded CPP-ACP(sCPP-ACP) to remineralize enamel sub-surface lesions was investigatedin a randomized, cross-over, double-blind in situ clinical study usingthe protocol of Reynolds et al. [Reynolds E. C. et al., (2003) J DentRes. 82, 206-211]. Ten subjects wore removable palatal appliances withsix, human enamel, half-slabs containing sub-surface demineralizedlesions prepared as described in Example 3. The other half of eachenamel slab was stored in a humidified container and was used as thecontrol demineralized lesion. There were seven treatments in the study,toothpaste B containing 0.2% w/w normal CPP-ACP, toothpaste C containing0.2% CPP-ACP/1.0% CaHPO₄ (referred to in FIG. 2 and Example 5 as “1.2%sCPP-ACP”), toothpaste E containing 1.0% CaHPO₄, toothpaste F containing1000 ppm F, toothpaste G containing 1.2% sCPP-ACP plus 1000 ppmF,toothpaste D containing 0.2% CPP-ACP/1.8% CaHPO₄ (referred to in FIG. 2and Example 5 as “2.0% sCPP-ACP”), and a control toothpaste A (placebo).The pastes were used for 30 s periods, four times per day. Theappliances were worn while using the paste and then for 1 hr after usingthe paste. Each treatment was for 14 days duration and each of the tensubjects carried out each treatment with a one week rest between thetreatments. At the completion of each treatment the enamel slabs wereremoved, paired with their respective demineralized control, embedded,sectioned and subjected to microradiography and computer-assisteddensitometric image analysis to determine the level of remineralization.The results presented as percentage enamel remineralization (% R) areshown in FIG. 2 and demonstrate that 0.2% CPP-ACP superloaded witheither 1.0% CaHPO₄ (1.2% sCPP-ACP) or 1.8% CaHPO₄ (2.0% sCPP-ACP)remineralizes enamel subsurface lesions significantly better than thenormal 0.2% CPP-ACP or the CaHPO₄ alone at the same concentration. The2.0% sCPP-ACP paste was significantly better than the paste containing1000 ppm fluoride. Further, 1.2% sCPP-ACP plus 1000 ppm F showed anadditive effect over 1.2% sCPP-ACP or 1000 ppm F alone.

EXAMPLE 5 Toothpaste Formulations Containing Superloaded CPP-ACP(sCPP-ACP)

Formulation 1 % w/v Ingredient 1 2 3 Sorbitol 53.0 53.0 53.0 Silica(Zeodent 119) 20.0 20.0 20.0 Purified water balance balance balanceSodium lauryl sulphate 4.0 4.0 4.0 sCPP-ACP 1.2 1.2 2.0 Sodiummonofluorophosphate 0.3 — — Flavour 1.0 1.0 1.0 Sodium carboxymethylcellulose 0.75 0.75 0.75 Titanium dioxide 0.525 0.525 0.525 Xanthan gum0.475 0.475 0.475 Sodium saccharin 0.350 0.350 0.350 pH adjusted to 7.0with phosphoric acid

Formulation 2 Ingredient % w/v % w/v % w/v Sorbitol 22.0 22.0 22.0 IrishMoss 1.0 1.0 1.0 Gantrez 19.0 19.0 19.0 Purified water balance balancebalance Sodium monofluorophosphate — — 0.76 Sodium saccharine 0.3 0.30.3 Pyrophosphate 2.0 2.0 2.0 Hydrated alumina 47.0 47.0 47.0 Flavour0.95 0.95 0.95 sCPP-ACP 1.0 2.0 2.0 Sodium lauryl sulphate 2.0 2.0 2.0pH adjusted to 5-7 with NaOH

Formulation 3 Ingredient % w/v Dicalcium phosphate dihydrate 45.0Sorbitol 10.0 Glycerol 10.0 Sodium carboxymethyl cellulose 1.0 Sodiumlauryl sulphate 1.5 Sodium lauryl sarconisate 0.5 Flavour 1.0 Sodiumsaccharine 0.1 Sodium monofluorophosphate 0.3 Chlorhexidine gluconate0.01 Dextranase 0.01 sCPP-ACP 5.0 Purified water balance pH adjusted to5-7 with phosphoric acid

Formulation 4 Ingredient % w/v Sorbitol 22.0 Irish moss 1.0 Gantrez 19.0Purified water balance Sodium saccharin 0.3 Pyrophosphate 2.0 Hydratedalumina 43.0 Sodium monofluorophosphate 0.3 Flavour 0.95 sCPP-ACP 5.0Sodium lauryl sulphate 2.0 pH adjusted to 5.5 with NaOH

Formulation 5 Ingredient % w/v Dicalcium phosphate dihydrate 45.0Sorbitol 10.0 Glycerol 10.0 Sodium carboxymethyl cellulose 1.0 Sodiumlauryl sulphate 1.5 Sodium lauryl sarconisate 0.5 Flavour 1.0 Sodiumsaccharine 0.1 Chlorhexidine gluconate 0.01 Dextranase 0.01 Sodiummonofluorophosphate 0.3 sCPP-ACP 5.0 Purified water balance pH adjustedto 5.5 with phosphoric acid

Formulation 6 % w/v Ingredient 1 2 Sorbitol 53.0 53.0 Silica (Zeodent119) 20.0 20.0 Purified water balance balance Sodium lauryl sulphate 4.04.0 sCPP-ACP 5.0 5.0 Sodium monofluorophosphate — 0.3 Sodium dihydrogenphosphate 1.45 1.45 Flavour 1.0 1.0 Sodium carboxymethyl cellulose 0.750.75 Titanium dioxide (Rutile) 0.525 0.525 Xanthan gum 0.475 0.475Sodium saccharin 0.350 0.350 Sodium fluoride 0.243 — pH adjusted to 5-7with phosphoric acid/NaOH

Formulation 7 % w/v Ingredient 1 2 Sorbitol (70% solution) 31.0 31.0Purified water balance balance Silica 17.0 17.0 Glycerol 8.0 8.0 Sodiumlauryl sulphate 4.0 4.0 Polyethylene glycol 300 1.0 1.0 Sodium fluoride0.243 — Titanium dioxide (Rutile) 0.525 0.525 Xanthan gum 0.475 0.475Sodium carboxymethyl cellulose 0.5 0.5 Sodium saccharine 0.286 0.286Sodium acid pyrophosphate 2.4 2.4 Tetra sodium pyrophosphate 2.2 2.2Flavour 1.0 1.0 sCPP-ACP 5.0 5.0 Sodium monofluorophosphate — 0.3 pHadjusted to 5-7 with phosphoric acid/NaOH

EXAMPLE 6 Mouthwash Formulations

Formulation 1 Ingredient % w/v Ethanol 10.0 Flavour 1.0 Sodium saccharin0.1 Sodium monofluorophosphate 0.3 Chlorhexidine gluconate 0.01 Lauroyldiethanolamide 0.3 sCPP-ACP 5.0 Water balance pH adjusted to 5.5 usingphosphoric acid/NaOH

Formulation 2 Ingredient % w/v Gantrez S-97 2.5 Glycerine 10.0 Flavouroil 0.4 Chlorhexidine gluconate 0.01 Lauroyl diethanolamide 0.2 sCPP-ACP5.0 Water balance pH adjusted to 5.5 using phosphoric acid/NaOH

EXAMPLE 7 Lozenge Formulation

Ingredient % w/v Sugar/sugar alcohol 75-80 Corn syrup  1-20 Flavour oil1-2 sCPP-ACP 5.0 Mg stearate 1-5 Water balance pH adjusted to 5.5 usingphosphoric acid/NaOH

EXAMPLE 8 Chewing Gum Formulation

Ingredient % w/v Gum base 30 Calcium carbonate 2.0 Crystalline sorbitol53.0 Glycerine 0.5 Flavour oil 0.1 sCPP-ACP 5.0 Water balance pHadjusted to 5.5 using citric acid

It will be understood that the invention disclosed and defined in thisspecification extends to all alternative combinations of two or more ofthe individual features mentioned or evident from the text or drawings.All of these different combinations constitute various alternativeaspects of the invention.

1. A phosphopeptide or phosphoprotein (PP) stabilised amorphous calciumphosphate or amorphous calcium fluoride phosphate complex having acalcium ion content greater than about 30 moles of calcium per mole ofPP.
 2. A complex according to claim 1, wherein the PP is caseinphosphopeptide (CPP).
 3. A complex according to claim 1, wherein thecalcium ion content is in the range of 30 to 50 moles of calcium permole of PP.
 4. An oral care formulation including a complex according toclaim
 1. 5. A method for producing a phosphopeptide or phosphoprotein(PP) stabilized amorphous calcium phosphate (ACP) and/or amorphouscalcium fluoride phosphate (ACFP) complex having a calcium ion contentgreater than about 30 moles of calcium per mole of PP including thesteps of: (i) obtaining a solution including a PP-ACP and/or PP-ACFPcomplex; and (ii) mixing with calcium and phosphate ions, whilemaintaining the pH of the solution at less than
 7. 6. A formulation of aPP stabilized ACP and/or ACFP complex together with at least an equalamount by weight of calcium phosphate.
 7. A formulation according toclaim 6, wherein the calcium phosphate is in the form of CaHPO₄.
 8. Anoral care formulation including a formulation according to claim
 7. 9. Amethod for remineralizing a dental surface or subsurface includingapplying to the dental surface or subsurface a phosphopeptide orphosphoprotein (PP) stabilized amorphous calcium phosphate or amorphouscalcium fluoride phosphate complex having a calcium ion content greaterthan about 30 moles of calcium per mole of PP.
 10. A method of treatmentand/or prevention of one or more of dental caries, dentalerosion/corrosion, dental hypersensitivity and dental calculus inanimals including humans including applying to a dental surface orsubsurface a phosphopeptide or phosphoprotein (PP) stabilized amorphouscalcium phosphate or amorphous calcium fluoride phosphate complex havinga calcium ion content greater than about 30 moles of calcium per mole ofPP.